The Human Body: An Introduction

Ch.1 / Exam #1

Anatomy

The various structures of the body, and their relationship to one another

Gross Anatomy

Structures visible to the naked eye

Microscopic Anatomy

Structures that are microscopic

Physiology

How these individual body parts function on a normal level

Principle of Complementarity of Structure & Function

What a structure can do is dependent on its form

Chemical Organization

Atoms combine to form molecules

Cellular Organization

The smallest unit of life

Tissue Organization

Aggregations of living cells that carry out a similar function

Organ Organization

Two or more tissues operate together to perform a certain function

Organ System Organization

Multiple organs work together

Organismal Organization

All organ systems working together to keep the organism alive

Function: Maintaining Boundaries

Separates some parts from other parts

Function: Movement

Cooperation of skeletal & muscular systems to coordinate actions; conscious or not

Function: Responsiveness

Sensing environmental changes and responding to them

Function: Digestion

Food is broken down to simple molecules to be absorbed to blood & delivered to various tissues

Function: Metabolism

The sum of all the chemical reactions in the body

Function: Excretion

Removal of waste produced during digestive & metabolic functions

Function: Reproduction

Cells must divide for survival; production of offspring

Function: Growth

Increase in the number of body cells, or increase in size of individual cells themselves; building must occur faster than breakdown

Survival Needs: Nutrients

Brough into body by ingestion

Survival Needs: Oxygen

Cells can only survive a few minutes without

Survival Needs: Water

Provides environment for chemical reactions and serves as fluid base for secretions and excretion

Survival Needs: Endothermy

Body temperature must be maintained for chemical processes to occur

Survival Needs: Atmospheric Pressure

Breathing and gas exchange occur at an appropriate level

Homeostasis

The maintenance of the internal condition of the body despite a constantly changing external environment, not a static state

Variable

What organ or function is being controlled or regulated to maintain homeostasis

Receptor

Respond to a change in variable dependent on body states

Control Center

Receive signals from receptors to determine if/what needs to be changed

Effector

Receive signals from control centers that makes the necessary changes

Negative Feedback Mechanism

Regulatory mechanism that causes the variable to change in a direction that is opposite of the initial change

Positive Feedback Mechanism

Cause the original change of the variable to be enhanced

Reference Point

Anatomical position; right vs. left is always viewed in terms of the person being observed

Directional Terms

Helps us explain one body part in relation to the others

What is the opposite of dorsal?

Ventral

What is the opposite of lateral (further away)? (Ex. eyes & ears)

Medial (closer)

What is the opposite of distal (further away)? (Ex. arms & legs)

Proximal (closer)

What is the opposite of deep? (Ex. heart & skin)

Superficial

What is the opposite of superior? (Ex. head & neck)

Inferior

Sagittal

Divides body into left and right (exactly in half)

Frontal

Divides body into anterior and posterior

Transverse

Divides body in superior and inferior parts

Dorsal Body Cavity

Protects organs of the central nervous system

What is the dorsal body cavity composed of?

The cranial & spinal cavity

Ventral Body Cavity

Houses visceral organs

Ventral Body Cavity: Thoracic Cavity

Contains heart & lungs

Ventral Body Cavity: Abdominopelvic Cavity

Contains the rest of the organs; separated by diaphragm

Serious Membrane (Serosa)

Double layered membrane

Serosa Membrane: Visceral

Innermost layer covering the organ

Serosa Membrane: Parietal

Outer layer lining the body wall of the cavity

How are the serosa layers separated?

Small amount of serous fluid to reduce friction

Pericardium Serous Membrane

Surrounding the heart

Pleura Serous Membrane

Surrounding the lungs

Peritoneum Serous Membrane

Surrounding most organs of the abdominopelvic cavity